When conducting certain railroad work alongside the track, a power shovel or material handling machine is mounted on a flat bottom service car. The power shovel, or the like, is employed to dig along the side of the track and load the material in the car. Conversely, the material handling device may be used to unload the car of material. In either case, the shovel or device travels the length of the car in doing its work and in so doing, can only reach and fill or unload two adjacent cars on either side of the car in which the shovel is mounted. To do other cars require switching cars in the train and locating the service car near a fresh empty or full car, as the case may be.
The U.S. Pat. No. 2,052,867 discloses a drop end railroad car which allows a train of these cars to provide a continuous platform as the length of the train of open top cars along which the power shovel or material handling device may be moved under its power while loading or unloading material in the cars. The drop ends of the adjacent cars extend flush with the car floors to form bridges for traveling from one car to the next of the train.